This invention relates to an electronically controlled sewing machine having an electronic memory for storing stitch pattern information. The stored information is accessed in such a way that it controls the stitch forming instrumentalities when sewing a stitch pattern.
Such sewing machines are well known in the art. See for example, U.S. Pat. No. 4,092,937, issued on June 6, 1978, to Landau, Jr. Et al, the teachings of which are incorporated herein by reference. Landau Jr. discloses a programmable sewing machine having internal memory for storing stitch pattern and other related data for controlling the sewing operation of the machine. A major disadvantage of this type of sewing machine is that a finite number of stitch patterns, usually a relatively small number, may be stored in the memory. This imposes a substantial limitation on the repertoire of stitch patterns that may be available for sewing on the machine thereby affecting its value to the consumer.
U.S. Pat. No. 4,160,422, issued on July 10, 1979 to Barber et al, the teachings of which are incorporated herein by reference, discloses a programmable sewing system including a sewing machine having an internal memory for storing stitch pattern data for controlling the sewing operation of the machine. An auxiliary memory unit is provided for storing stitch pattern data which may be entered into the internal memory of the sewing machine for sewing a particular stitch pattern or a series of stitch patterns. The auxiliary memory unit is capable of receiving a replaceable memory medium such as a tape cassette or floppy disc, which can accommodate a relatively large quantity of stitch pattern data. Economic realities and other considerations generally require that many stitch patterns be stored on a given cassette or disc. A major disadvantage of this system is that the stitch pattern data residing on the tape or disc for a particular stitch pattern is not readily identifiable by the operator. The operator must perform an extremely difficult and tedious search of the magnetic cassette tape or disc which may contain hundreds of different stitch patterns in order to locate the desired one.
Another disadvantage of this system is the difficulty of adding a new stitch pattern to the auxiliary memory. Should a sewing machine manufacturer wish to make available a new stitch pattern to all its customers having such a system, it would have to distribute to each customer a replacement cassette tape or disc hwaving all the old stitch patterns including the new one, or it would have to distribute a cassette tape or disc containing only the new stitch pattern and provide a means by which it may be added to the existing tape or disc. The first solution would be impractical if the cassette tapes in the field were not identical; that is, if they contained different collections of stitch patterns to meet the varying needs of individual customers. The manufacturer would probably not want to incur the expense and administrative work involved in keeping track of these various configurations. The second solution is equally undersirable since there would be substantial cost involved in providing each customer with a cassette tape or disc having a single stitch pattern recorded thereon.
What is needed is a storage medium that is not adversely affected by direct operator handling, requires no special enclosure, and can economically contain data for a single stitch pattern. There should be some means by which the operator may easily identify data stored within the storage medium through a visual representation of the stitch pattern that is embodied in the data.